With your king in front of a rook pawn or knight pawn, you can keep your rook on the back rank and wait: the attacker can't make progress. Against other pawns that only works while the enemy king hasn't reached your third rank; after that, check from behind. When your king is cut off from the pawn but the pawn is still back, check from in front instead, with at least three ranks between your rook and the pawn, or offer the rook trade if the king and pawn ending is drawn.
Every move is checked with an endgame tablebase, which knows the exact result of every position with up to seven pieces. The computer defends perfectly, and if a move throws the result away, the trainer stops and shows you a better one.
